I have been testing the new Super-2 upgrade which includes the 2000 series drivers. I can say that from an older original OW2, the upgrade made a very big improvement. The bass goes a bit lower and is a little more solid, and the tweeters are a nice improvement as well, smoother, not as peaky/bright, especially on recordings that tend to be a little "hotter" to begin with.
I think they are very much as John Strohbeen says on the website, they are an "evolutionary versus revolutionary" upgrade. They still retain all the things that make an Ohm an Ohm, just make it better.
I do not know how much of an upgrade it would be from the series 3 drivers as I don't have anything to compare them with right now. I would think that if they are in good condition that this upgrade may be a bit better, but whether it is worth the added costs would be up to the listener. The great things is, you can always try them and if not satisfied, send them back! You can't get any better than that!
As to the actual installation, it isn't bad really, the hardest part is getting the crossover/switches out of the bottom. If you have short arms, it is a little challenging, especially if you are wanting to keep that board all in one piece. The old drivers just unscrew off the top mounting plate of the cabinet, and a newer mounting board with the new 2000 drivers is then mounted with 4 wood screws to the top of the cabinet. Easy. You get a new taller grill to fit, as the newer driver is a little bigger and the mounting puts it about 1/2" or so taller than stock.
There are some mounting details I have been working on with regard to the top driver board and a couple of other things that would make for a nicer appearance. This is trivial for those who would always use the cloth grill covers anyway. The main thing is that they do sound great and worth the upgrade from the original! Very well recommended!
I can't say enough about John and company, and the ability to provide upgrades to a product that is pushing 30-years old. Don't forget that Ohm also has older cabinets and they can refinish and upgrade to the newer drivers for a bit less than the new series. There are some nice options for those inclined to go that route. Enjoy your music! Tim